Pneumato-electric piano-player.



G. BUEGHNER & H. SEMRAU.

PNEUMATO ELECTRIC PIANO PLAYER.

APPLICATION FILED AUG. 16, 1912.

lla.

WITNESSES, INVENTORS.

1-1 1 TEE A TTORNEY.

GUENTHER BUECHNER AND HUGO SEMEAU, OF SCHENEGTADY, NEW YORK.

INEUMATO-ELECTRIC PIANO-PLAYER.

Specification of Letters Patent.

Patented Sept. 23, 1913.

I Application filed August 16, 1912. Serial No. 715,368.

To all whom it may concern Be it known that we, GUENTHER BUEOH- NER and HUGO SEMRAU, subjects of the Emperor of Germany, and residents of the city of Schenectady, county of Schenectady, and State of New York, have invented certain new and useful Improvements in Pneumato- Electric Piano-Players, of which the following is a specification.

The invention relates to such improvements and consists of the novel construction and combination of parts hereinafter described and subsequently claimed.

Reference may be had to the accompanying drawings, and the reference characters marked thereon, which form a part of this specification. Similar characters refer to similar parts in the several figures therein.

Figure 1 of the drawings is a bottom plan view of a part of the air-chamber or box showing several of the'contact-making-and breaking units in position for use. Fig. 2 is a side view of the same as shown in Fig. 1. Fig. 3 is a cross-section taken on the line 33 in Fig. 1 through two of the circuitmaking-and-breaking units provided with different forms of spark-arresters in accordance with our invention. Fig. 4 is a view similar to Fig. 3 showing the spark-arrester as a preferred form of condenser. Fig. 5 is an inner end view of one of the circuit-making-and-breaking units detached. Fig. 6 is a diagrammatic view illustrating the use of a discharge resistance as a spark arrester. Fig. 7 is a similar diagrammatic view illustrating the use of a condenser as a spark-arrester.

Certain features of the invention are applicable to different kinds of piano players, butin its preferred form the invention is particularly adapted for piano players wherein the keys are operated by electromagnets, the operation of which is controlled by a pneumatic contact-making-andbreaking apparatus adapted for use with a perforated music-sheet.

Certain features of the invention are to facilitate the operation of the contacts in making and breaking the circuit; to simplify the system of wiring; to facilitate repairof the contact-making-and-breaking devices; and to preventsparking-of the contact-breaking device.

Other objects of the invention will appear in connection with the following description.

Referring to the drawings wherein the invention is shown in preferred form, the airchamber or box, 1, is constantly kept under 5. A series of ducts, 6, connect the respecv tive auxiliary air-chambers, 3, with the openings in a tracker-board for a perforated musicsheet, which forms no part of our invention and which may be of any known form whereby the several auxiliary airchambers, 3, are at certain times open to, and at certain other times closed to, the atmosphere.

As is well understood by those familiar with pneumatically operated piano players, whenever the auxiliary air-chamber, 3, is closed to the atmosphere, the pressure upon opposite sides of the diaphragm, 4 or 4, will be equalized through the bleed, 5, and whenever an auxiliary air-chamber, 3, is open to the atmosphere, the atmospheric pressure upon the outer side of the diaphragm, 4 or 4*, will exceed the main airchamber pressure on the'inner side of said diaphragm causing the diaphragm, which is flexible and adapted to yield, to bulge inwardly as shown at 4 in Fig. 4. When not exposed to atmospheric pressure, the diaphragm extends straight across the back of the auxiliary air-chamber as shown at 4 in Fig. 4.

Our invention relates more particularly to means for utilizing this bulging or displacement of the diaphragm to close an electriccircuit containing an electro-magnet by on ergization of which-a piano key is operated.

As the electro-magnetic means for operating the piano key forms nopart of the present invention, we have omitted the same from the drawings.

In carrying out our invention, we provide the main air-chamber, 1, with a series of socket-apertures, 7, opposite the respective auxiliary air-chambers, 3, each of said sockets being adapted to receive a circuitmaking-and-breaking unit and support the same in operative relationship to the respective diaphragm, 4. One of these circuitmaking-and-breaking units is shown removed in Fig. 5. Each of these circuitmaking-and-breaking units comprises an inpoint, 11, is located in the path of a spring- 1 contact, 12, mounted upon the inner end of the sleeve, 9, in position when the unit is inserted in one of the sockets, 7, to be engaged and operated by the oppositely located diaphragm, i, when the latter is bulged or displaced inwardly as shown at 4 in Fig. 4c. As soon as the diaphragm is relieve-d from atmospheric pressure, it returns to the position shown at at in Fig. 4:, whereupon the spring-contact, 12, automatically separates from the contact point, 11, to break the circuit. One side of the circuit is connected by a wire, 13, with the binding post, 10, and the other side of the circuit is connected through a bus-bar, 14, with the sleeve, 9, said bus-bar being located in the path of, and adapted to frict-ionally engage, said sleeve as the unit is inserted in the socket, 7.

To prevent sparking upon the breaking of the connection between the contacts, 11 and 12, we provide each of the circuit-making-and-breaking units with a contained spark-arrester. For certain purposes of the invention the contained spark-arrester may be of any known form adapted to comprise a part of the removable circuit-making-andbreaking unit. In Fig. 3 we have shown two forms of contained spar'k-arrester, one being a discharge resistance, 15, permanently connecting the sleeve, '9, with the binding post, 10. This discharge resistance, 15, is formed by a coil wound upon a spool, 16, fixed upon the head or base, 8, one end of the coil being connected with the sleeve and the other end with the binding post, 10.

To illustrate the operation of the dis:

charge resistance, reference may be had to Fig. 6 wherein 11 represents the contact point, 11, on the binding post; 12 the spring contact, 12; 15 the discharge resistance, 1o; 18 the battery or generator; and 19 the electro-magnet. The. dischargeresistance, 15*, forms a constant connection between the opposite sides of the switch, permitting the passage of sufficient current to relieve or .arrest the sparking while not permitting the passage of sufli-cient current to energize the electro-magnet, 19. Any known form of discharge-resistance adapt ed to form a constituent part of the removable circuit-inaking-andabreakin'g unit may be employed. We have also shown a sparkarrester in the form of a condenser, 20, consisting of alternately arranged perforated disks of conductive and insulating material located within the sleeve, 21, encircling the post, 10, said conductive disks :being connected in alternation with the sleeve 9,

and with the post, 10, through an inner sleeve, 21.

In Fig. 4 we have shown a spark-arrester in the form of a condenser, 22, the alternate conductive and insulating or dielectric, elements of which are spirally wound about the post, 10, within the sleeve, 9.

To illustrate the operation of the condenser as a spark-arrester, reference may be had to Fig. 7 wherein the parts are designated similarly to the parts in Fig. 6, except that a condenser, 20 is shown in place of the spark-coil, 15

The circuit making and breaking units above described are readily removed tor-examination and repair and are interchangeable with "one another in their relationship to the sockets, 7, and to the diaphragms, 4.

That we claim as new and desire to secure by Letters Patent is 1. In a piano-player, and in combination, an air-chamber having a pneumatically operated diaphragm; and a circuit-makingand-breaking unit removably mounted upon said air-chamber opposite said diaphragm, said unit comprising a movable contact located in the path of said diaphragm in electrical connection with one side of an electric circuit, and contact in the path of said movable contact in electrical connection with the other side of said circuit.

2. In a piano-player, and in combination, an air-box provided with a plurality of airchambers and with :a like plurality ofsocketopenings opposite the respective air-chambers; pneumatically operated diaphragms for the respective air-chambers; and a like plurality of circuit-makingand-breaking units interchangeably insertible in the respective socket-openings, each of said units comprising a movable contact located in the path of said diaphragm in electrical connection with one side of an electric circuit, and a contact in the path of said movable contact in electrical connection with the other side of said circuit.

:8. In a piano-player, and in combination, an air-chamber having a pneumatically operated diaphragm; and a circuit-makingand-breaking unit removably mounted upon said air-chamber opposite said diaphragm, sa'id unit comprising a movable contact located in the path oi said diaphragm in elec trical connection with one side of an electric circuit, a contact in the path of said movable contact in electrical connection with the other side of said circuit, and a spark arrester.

4. In a pianoplayer, and in combination, an air-chamber having a pneumatically operated diaphragm; and a circuit-makingand-breaking unit removably supported upon said air-chamber opposite said diaphragm, said unit comprising a conductive sleeve in electrical connection with one side of an electric circuit, a spring-contact mounted upon the inner end of said sleeve in the path of said diaphragm, and a contact in the path of said spring-contact in electrical connection with the other side of said circuit.

5. In a piano-player, and in combination, an air-chamber having a pneumatically operated diaphragm; and a circuit-makingand-breaking unit supported upon said airchamber opposite said diaphragm, said unit having a contained spark-arrester.

6. Ina piano-player, and in combination, an air chamber having a pneumatically operated diaphragm; and a circuit-makingand breaking unit supported upon said airchamber opposite said diaphragm, said unit having a contained condenser.

7. I11 a piano-player, and in combination, an air-chamber having a pneumatically operated diaphragm; and a circuit-makingand-breaking unit removably supported upon said air-chamber opposite said diaphragm, said unit comprising a conductive sleeve in electrical connection with one side of an electric circuit, a movable Contact mounted upon the inner end of said sleeve in the path of said diaphragm, an insulating base, a binding post having a contact in the path of said movable contact, and a con denser contained within said sleeve surrounding said binding post in electrical connection with said sleeve and post.

8. In a piano-player, and in combination, an air-chamber having a pneumatically operated diaphragm and opposite thereto a socket; a circuit-making-and-breaking unit removably inserted in said socket, said unit comprising a conductive sleeve, a spring contact mounted upon the inner end of said sleeve in the path of said diaphragm, and a contact in the path of said spring contact in electrical connection with one side of an electric circuit; and a terminal-plate in electrical connection with the other side of said circuit permanently mounted upon said airchamber in the path of said sleeve when said unit is inserted within the socket.

In testimony whereof, we have hereunto set our hands this 9th day of August, 1912.

GUENTHER BUECI-INER. HUGO SEMRAU. Witnesses:

W. L. HORTON, ORVILLE WV. BLODGETT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

